/*
 *     Android基础开发个人积累、沉淀、封装、整理共通
 *     Copyright (c) 2016. 曾繁添 <zftlive@163.com>
 *     Github：https://github.com/zengfantian || http://git.oschina.net/zftlive
 *
 *     Licensed under the Apache License, Version 2.0 (the "License");
 *     you may not use this file except in compliance with the License.
 *     You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 *     Unless required by applicable law or agreed to in writing, software
 *     distributed under the License is distributed on an "AS IS" BASIS,
 *     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *     See the License for the specific language governing permissions and
 *     limitations under the License.
 */

package com.zftlive.android.library.zxing.decode;

import android.app.Activity;
import android.content.ActivityNotFoundException;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.provider.Browser;
import android.util.Log;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.DecodeHintType;
import com.google.zxing.Result;
import com.zftlive.android.library.zxing.CaptureActivity;
import com.zftlive.android.library.zxing.R;
import com.zftlive.android.library.zxing.camera.CameraManager;
import com.zftlive.android.library.zxing.view.ViewfinderResultPointCallback;

import java.util.Collection;
import java.util.Map;

/**
 * This class handles all the messaging which comprises the state machine for
 * capture.
 *
 * @author dswitkin@google.com (Daniel Switkin)
 */
public final class CaptureActivityHandler extends Handler {

  private static final String TAG = CaptureActivityHandler.class
          .getSimpleName();

  private final CaptureActivity activity;

  /**
   * 真正负责扫描任务的核心线程
   */
  private final DecodeThread decodeThread;

  private State state;

  private final CameraManager cameraManager;

  /**
   * 当前扫描的状态
   */
  private enum State {
    /**
     * 预览
     */
    PREVIEW,
    /**
     * 扫描成功
     */
    SUCCESS,
    /**
     * 结束扫描
     */
    DONE
  }

  public CaptureActivityHandler(CaptureActivity activity,
                                Collection<BarcodeFormat> decodeFormats,
                                Map<DecodeHintType, ?> baseHints, String characterSet,
                                CameraManager cameraManager) {
    this.activity = activity;

    // 启动扫描线程
    decodeThread = new DecodeThread(activity, decodeFormats, baseHints,
            characterSet, new ViewfinderResultPointCallback(
            activity.getViewfinderView()));
    decodeThread.start();

    state = State.SUCCESS;

    // Start ourselves capturing previews and decoding.
    this.cameraManager = cameraManager;

    // 开启相机预览界面
    cameraManager.startPreview();

    restartPreviewAndDecode();
  }

  @Override
  public void handleMessage(Message message) {
    int resId = message.what;
    // 准备进行下一次扫描
    if (R.id.restart_preview == resId) {
      Log.d(TAG, "Got restart preview message");
      restartPreviewAndDecode();
    } else if (R.id.decode_succeeded == resId) {
      Log.d(TAG, "Got decode succeeded message");
      state = State.SUCCESS;
      Bundle bundle = message.getData();
      Bitmap barcode = null;
      float scaleFactor = 1.0f;
      if (bundle != null) {
        byte[] compressedBitmap = bundle
                .getByteArray(DecodeThread.BARCODE_BITMAP);
        if (compressedBitmap != null) {
          barcode = BitmapFactory.decodeByteArray(
                  compressedBitmap, 0, compressedBitmap.length,
                  null);
          // Mutable copy:
          barcode = barcode.copy(Bitmap.Config.ARGB_8888, true);
        }
        scaleFactor = bundle
                .getFloat(DecodeThread.BARCODE_SCALED_FACTOR);
      }
      activity.handleDecode((Result) message.obj, barcode,
              scaleFactor);
    } else if (R.id.decode_failed == resId) {
      // We're decoding as fast as possible, so when one decode fails,
      // start another.
      state = State.PREVIEW;
      cameraManager.requestPreviewFrame(decodeThread.getHandler(),
              R.id.decode);
    } else if (R.id.return_scan_result == resId) {
      Log.d(TAG, "Got return scan result message");
      activity.setResult(Activity.RESULT_OK, (Intent) message.obj);
      activity.finish();
    } else if (R.id.launch_product_query == resId) {
      Log.d(TAG, "Got product query message");
      String url = (String) message.obj;

      Intent intent = new Intent(Intent.ACTION_VIEW);
      intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET);
      intent.setData(Uri.parse(url));

      /**
       * 这段代码是zxing项目组想要用chrome打开浏览器浏览url
       */
      ResolveInfo resolveInfo = activity.getPackageManager()
              .resolveActivity(intent,
                      PackageManager.MATCH_DEFAULT_ONLY);
      String browserPackageName = null;
      if (resolveInfo != null && resolveInfo.activityInfo != null) {
        browserPackageName = resolveInfo.activityInfo.packageName;
        Log.d(TAG, "Using browser in package " + browserPackageName);
      }

      // Needed for default Android browser / Chrome only apparently
      if ("com.android.browser".equals(browserPackageName)
              || "com.android.chrome".equals(browserPackageName)) {
        intent.setPackage(browserPackageName);
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        intent.putExtra(Browser.EXTRA_APPLICATION_ID,
                browserPackageName);
      }

      try {
        activity.startActivity(intent);
      } catch (ActivityNotFoundException ignored) {
        Log.w(TAG, "Can't find anything to handle VIEW of URI "
                + url);
      }
    }
  }

  public void quitSynchronously() {
    state = State.DONE;
    cameraManager.stopPreview();
    Message quit = Message.obtain(decodeThread.getHandler(), R.id.quit);
    quit.sendToTarget();

    try {
      // Wait at most half a second; should be enough time, and onPause()
      // will timeout quickly
      decodeThread.join(500L);
    } catch (InterruptedException e) {
      // continue
    }

    // Be absolutely sure we don't send any queued up messages
    removeMessages(R.id.decode_succeeded);
    removeMessages(R.id.decode_failed);
  }

  /**
   * 完成一次扫描后，只需要再调用此方法即可
   */
  private void restartPreviewAndDecode() {
    if (state == State.SUCCESS) {
      state = State.PREVIEW;

      // 向decodeThread绑定的handler（DecodeHandler)发送解码消息
      cameraManager.requestPreviewFrame(decodeThread.getHandler(),
              R.id.decode);
      activity.drawViewfinder();
    }
  }

}
